Process for protecting a substrate with an n{11 aryl substituted arylsulfonamide intumescent agent

ABSTRACT

Intumescent compositions of the invention comprise certain N1aryl substituted arylsulfonamides, such as sulfanilamidobenzene, sulfanilamidonaphthalene, and derivatives thereof. The intumescent agents may be employed in conjunction with additives conventionally used in intumescent compositions. For use in protecting substrates from heat and fire, the intumescent compositions may be applied to the substrate in any suitable manner, such as by electro-deposition, spraying onto an adhesive substrate, or application of a coating composition comprising the intumescent agent.

wrutcu blalflb l Roth PROCESS FOR PROTECTING A SUBSTRATE WITH AN N -ARYL sFBsTITuTEn ARYLSULFONAMIDE INTUMESCENT AGENT Shirley 11. Roth, Highland Park, NJ.

Cities Service Company, New York, N.Y.

Feb. 11, 1972 Inventor:

Assignee:

Filed:

App]. No.:

US. Cl. 117/136, 106/15 FP Int. Cl. C09d 5/18, C09k 3/28 Field of Search.. 117/136; 106/15 FP; 252/8.1

References Cited UNITED STATES PATENTS 10/1970 Webb 117/136 X 5/1972 Sawko.... 117/136 X 12/1972 Hardy 117/136 X Oct. 30, 1973 OTHER PUBLICATIONS Northey, Sulfonamides, pps. 23, 58-59 (1948).

Primary ExaminerWi1liam D. Martin Assistant ExaminerHarry J. Gwinnell AttorneyPatricia J. Hogan et a1.

[57] ABSTRACT agent.

4 Claims, No Drawings 1 PROCESS FOR PROTECTING A SUBSTRATE WITH AN N ARYL SUBSTITUTED ARYLSULFONAMIDE INTUMESCENT AGENT BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to intumescent compositions and more particularly relates to such compositions containing a one-component intumescent agent.

2. Description of the Prior Art It is known that a substrate may be protected from heat and fire by the application of an intumescent composition. lntumescent compositions of the prior art usually contain an intumescent agent having at least three components; i.e., a carbonific, a spumific, and a catalyst; and they are typically characterized by the disadvantages of high cost, low spreading rate, relatively poor efficiency, poor water resistance, and poor weatherability.

As disclosed in U.S. Pat. No. 3,535,130, it has already been discovered that a one-coponent intumescent agent has advantages over multicomponent intumescent agents. However, the intumescent agents of the patent have poor adherence to substrates and have an undesirable degree of moisture sensitivity.

SUMMARY OF THE INVENTION An object of this invention is to provide a novel class of one-component intumescent agents.

Another object is to provide such intumescent agents having good efficiency and a low level of moisture sensitivity.

These and other objects are attained by using as intumescent agents compounds corresponding to the formula:

wherein Ar is a divalent aromatic residue, R is hydrogen, hydrocarbon, halohydrocarbon, or acyl, and R" is an aromatic hydrocarbon or substituted hydrocarbon radical.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The intumescent agents of the invention may be any compounds corresponding to the above formula. However, they are preferably compounds wherein Ar is a divalent aromatic residue derived from benzene or naphthalene or an alkyl, haloaklyl, alkoxy, haloalkoxy, halo, hydroxy, carboxy, amino, amido, or nitro derivative thereof. When the aromatic ring bears organic substituents, it is usually preferred that these substituents contain one to five carbon atoms. When there are halo substituents, it is usually preferred that they be chloro or bromo. It is also preferred that the aromatic ring have at least one free reactive position.

As indicated above, R of the formula may be hydrogen or a hydrocarbon, halohydrocarbon, or acyl radical, e.g., an alkyl, chloroalkyl, or bromoalkyl radical containing one to five carbon atoms, a phenyl, chlorophenyl, or bromophenyl radical, or an aliphatic or aromatic acyl radical.

R"is preferably a phenyl, naphthyl, or other unsubstituted aromatic hydrocarbon radical, but it may bear one or more substituents if desired. The substituted aromatic hydrocarbon radicals most commonly found in these compounds are the chloro, bromo, fluoro, iodo, C,C alkyl, C -C haloalkyl, C -C alkoxy, oxy, keto, hydroxy, car'boxy, amino, amido, nitro, thio, sulfino, sulfo, sulfonamido, and phenyl derivatives, but compounds containing other substituted aromatic hydrocarbon radicals are also utilizable. When R" is a substituted aromatic hydrocarbon radical, the nitrogen of the sulfonamide group may be attached directly to the aromatic ring, or it may be attached to the aromatic ring through the substituent.

Exemplary of the intumescent agents of the invention are sulfanilamidobenzene, sulfanilamido- 1 naphthalene, sulfanilamido-2-naphthalene, 4-amino-3- chlorobenzenesulfonamidobenzene, 3-amino-4- bromobenzenesulfonamidobenzene, 4-amino2- ethylbenzenesulfonamidobenzene, 3 -amino-4- chloromethylbenzenesulfonamidobenzene, 4-amino-2- butoxybenzenesulfonamidobenzene, 4-amino-3- chloromethoxybenzenesulfonamidobenzene, 4-amino- 3 -carboxybenzenesulfonamidobenzene 3 ,4- diaminobenzenesulfonamidobenzene, 4-amino-2- acetamidobenzenesulfonamidobenzene 2-amino-4- bromophenylamino)benzenesulfonamidobenzene, pacetamidobenzenesulfonamidobenzene, pbenzamidobenzenesulfonamidobenzene, 2-chlorol sulfanilamidobenzene, 4-bromo-1- sulfanilamidobenzene, 3 ,S-dibromo-l sulfanilamidobenzene, 4-fluorol sulfanilamidobenzene, 4-iodo-1-sulfanilamidobenzene, 2,6-dimethyl lsulfanilamidobenzene, 3 ,5- di( trifluoromethyl l -sulfanilamidobenzene, 3- methoxyl -sulfanilamidobenzene 4-phenoxy- 1 sulfanilamidobenzene, N-(p-aminobenzenesulfonyl)- benzamide, 2-hydroxy-l-sulfanilamidobenzene, 3- carboxy-l-sulfanilamidobenzene, 3-carboxy-2- hydroxyl -sulfanilamidobenzene, 2-aminol sulfanilamidobenzene, 4-aminoethyll sulfanilamidobenzene, 3-amino-4-hydroxyl sulfanilamidobenzene, 4-nitro-1-sulfanilamidobenzene, 4-methylthiol -sulfanilamidobenzene, 4-nitro-2-sulfinol -sulfanilamido benzene, 4-sulfol sulfanilamidobenzene, p-sulfanilamidobenzenesulfonamide, 4-phenyl-l-sulfanilamidobenzene, l-phenyl-2- sulfanilamidoethane, the corresponding aminonaphthalenesulfonamide compounds, the corresponding N- naphthalene compounds, etc. When not readily available, these compounds may be prepared by known techniques.

For use in protecting a substrate from heat and fire, the intumescent agents of the invention may be applied in any suitable manner, e.g., electrodeposition, spraying of powdered intumescent agent onto an adhesive substrate, etc. However, it is usually preferred to compound the intumescent agent with a binder, e.g., nitrocellulose, and optionally also with one or more of the other ingredients conventionally used in intumescent compounds, e.g., stabilizers, dispersing agents, pigmerits, driers, biocides, anti-foamers, thickeners, protective colloids, fillers, blowing agents, etc.; disperse the composition in a suitable liquid medium, e.g., water or a solvent or solvent mixture; and apply the coating composition thus formed to the substrate to be protected. As is the case with conventional intumescent coating compositions, it is frequently convenient to apply these coating compositions in the form of a paint having a solids content of about 70 percent by weight and an intumescent agent/binder ratio of about 0.075-14/1 to deposit a coating having a dry thickness of about 0.0010.75 inch.

The intumescent agents of the invention are efficient, have low moisture sensitivity, and intumesce to form foams having good volume, cell structure, and adherence to substrates, such as wood, metal, and plastics. They are also useful as flame retardants in normally flammable compositions.

The following example is given to illustrate the invention and is not intended as a limitation thereof.

EXAMPLE I Place 1 gram of sulfanilamidobenzene in an aluminum pan and flame it with a propane torch. The compound intumescesto form an excellent volume of foam having a good cell structure.

Similar results are also observed when sulfanilamidol-naphthalene and the other intumescent agents mentioned in the specification are substituted for the intumescent agent of the example.

it is obvious that many variations may be made in the products and processes set forth above without departing from the spirit and scope of this invention.

What is claimed is:

11. A process for protecting a substrate from heat and fire which comprises applying thereto an intumescent composition comprising as the intumescent agent a compound corresponding to the formula:

wherein Ar is a divalent aromatic residue, R is hydrogen, hydrocarbon, halohydrocarbon, or acyl, and R" is an aromatic hydrocarbon or substituted hydrocarbon radical.

2. The process of claim 1 wherein Ar is a divalent aromatic residue derived from benzene or naphthalene or an alkyl, haloalkyl, alkoxy, haloalkoxy, halo, hydroxy, carboxy, amino, amido, or nitro derivative thereof.

3. The process of claim 11 wherein R" is a phenyl or naphthyl radical or an alkyl, haloalkyl, alkoxy, halo, oxy, keto, hydroxy, carboxy, amino, amido, nitro, thio, sulfino, sulfo, sulfonamido, or aryl derivative thereof.

4. The process of claim 11 wherein the intumescent agent is sulfanilamidobenzene.

gz g UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,769,075 Dated October 30, 1973 Invent0 Shirlev H. Roth It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

F "I Column 1, line 2, "N" should read N column 1, line 21, "coponent" should read component column 1, line 39, the portion of the formula reading "NHR" should read NHR" Column 4, line 12, the portion of the formula reading "NHR" should read NHR" Signed and sealed this 23rd day of April 19714..

(SEAL) Attest:

EDWAILD PLFLETGHERJRD C. MARSHALL DAI-IN Attesting Officer Commissioner of Patents 

2. The process of claim 1 wherein Ar is a divalent aromatic residue derived from benzene or naphthalene or an alkyl, haloalkyl, alkoxy, haloalkoxy, halo, hydroxy, carboxy, amino, amido, or nitro derivative thereof.
 3. The process of claim 1 wherein R'''' is a phenyl or naphthyl radical or an alkyl, haloalkyl, alkoxy, halo, oxy, keto, hydroxy, carboxy, amino, amido, nitro, thio, sulfino, sulfo, sulfonamido, or aryl derivative thereof.
 4. The process of claim 1 wherein the intumescent agent is sulfanilamidobenzene. 